So today in an attempt to trouble shoot my SRS issue I pulled the generic chinese ELM 327 BT dongle adapter from my F150 and plugged it into the wifes Tahoe and immediately something happened. The Service Stabilitrac and Service Traction Control messages were displayed. BT reader plugged in, key turns to on and BOOM messages.
So I ignored and fired up my laptop running ScanXL and the app refused to connect to the CAN bus/PCM. Also something else.. I went to start the engine to see if ScanXL would connect and it would not start. Like she wouldnt even turn over.
So I turned the key off, pulled the BT adapter and then it cranked up. Odd I thought, so with it running I plugged teh BT adapter back in and the engine started running rough, like it wanted to die. Ok that's an obvious sign somethings amiss!
I killed the engine and removed the BT adapter then plugged in my Innove code reader, turned the key to ON nd the code I was given was a permanent U0100 Lost comms to ECM/PCM. Well that's just great, so I pulled the negative battery cable off for a solid 10 minutes while I googled for reasons for this to happen... i found nothing.
After 10-15 minutes I put teh cable back on and it started right up. I let it idle for a good 30-45 seconds, then drove it around the block. Drove just fine. Now I have read where the procedure to clear perm codes is a lot more work than regular DTCs.

So the culprit is this cheap elm adapter but why? It works on my '09 F150 just fine, it also worked on a '00 Sierra 4x4.

Hopefully someone here has some insight. THanks.